Two baseballs are thrown from the roof.
of a house with the same initial speed,
one is thrown up, and the other is down,
compare the speeds of the baseballs
just before they hit the ground.

When the velocity of an object is doubled, by what factor is its momentum changed? by what factor is its kinetic energy changed? a) the momentum is zero. b) the momentum is not zero. c) difficult to say.

Ascrew incorporates which other simple machine? lever wheel and axle inclined plane pulley

Explain to someone who knows nothing about fossils the study of invertebrate paleontology and how it scientists understand the history of the earth. be sure your explanation contains a minimum of two complete sentences.